Transition-element doping effects in La0.7Ca0.3MnO3

The influence of transition element (TE) doping on the magnetotransport pro perties of La0.7Ca0.3MnO3 is studied for the entire transition element seri es (TE=Cr, Fe, Co, Ni, Cu, Zn) for a fixed (5% at Mn sites) dopant concentr ation. The systematics of different properties such as the metal-insulator transition temperature T-p, the Curie temperature T-c, rho(T-p), rho(5 K), and the maximum value of magnetoresistance (MR), with respect to lattice pa rameter and the ionic radii of dopants, are examined. The important finding s include an interesting correlation between the maximum MR, the lattice pa rameter, and the ionic radii, and some distinct features exhibited by Fe, C u, and Zn dopants. [S0163-1829(98)01146-1].